Hi Stephen, On 11/20/2014 08:41 AM, Stephen Burke wrote: > I woke up this morning to my pc not booting saying that my raid was in > a degraded state. I looked at the raid wiki and it told me to stop > what I was doing and mail the linux-raid list before doing anything > hasty. :-) > Here's all the info that I could find out about it. Any help would be > appreciated. > I am running Ubuntu 12.04 > mdadm - v3.2.5 - 18th May 2012 > > The drive in question is /dev/sdb1 on my system. I tried to look at > it via fdisk but it hangs up. What should my first steps to figure > out if this drive is bad and if so replace it. Thanks. Good news: your data is still safe, and already assembled (ready to use). The boot failure is a one-time warning that the number of drives available at shutdown didn't match the available drives at bootup. > syslog > > Nov 20 01:14:53 ht-pc kernel: [ 2.465076] res > 41/40:08:09:08:00/00:00:00:00:00/00 Emask 0x409 (media error) <F> > > Nov 20 01:14:53 ht-pc kernel: [ 2.465078] ata2.00: status: { DRDY ERR } > > Nov 20 01:14:53 ht-pc kernel: [ 2.465079] ata2.00: error: { UNC } > > Nov 20 01:14:53 ht-pc kernel: [ 2.484536] ata2.00: configured for UDMA/133 > > Nov 20 01:14:53 ht-pc kernel: [ 2.484543] ata2: EH complete > > Nov 20 01:14:53 ht-pc kernel: [ 3.131754] ata2.00: exception Emask > 0x0 SAct 0x40 SErr 0x0 action 0x0 > > Nov 20 01:14:53 ht-pc kernel: [ 3.131756] ata2.00: irq_stat 0x40000008 > > Nov 20 01:14:53 ht-pc kernel: [ 3.131758] ata2.00: failed command: > READ FPDMA QUEUED > > Nov 20 01:14:53 ht-pc kernel: [ 3.131762] ata2.00: cmd > 60/08:30:08:08:00/00:00:00:00:00/40 tag 6 ncq 4096 in > > Nov 20 01:14:53 ht-pc kernel: [ 3.131763] res > 41/40:08:09:08:00/00:00:00:00:00/00 Emask 0x409 (media error) <F> Bad news: that drive is very likely dead. It didn't communicate at all. If you replace the drive and the replacement works, I would count that as definitively a bad drive. But it could be a cable or controller problem. Such things happen. Before adding the new drive, though, I would show the "mdadm -E" reports for each of the surviving member devices. Just in case you encounter a problem during rebuild (ridiculously common for big drives in raid5). Anyways, use "mdadm /dev/md0 --add /dev/sdX1" after you partition the new drive. That'll start the rebuild. Phil -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html